Messages

1

General Questions and Answers / Optimization using initial steps

« on: January 15, 2018, 06:07 »

using initial steps  for dft calculation greatly reduces the time when we have to calculate for a higher mesh cutoff,  but can we apply the same technique for geometry optimization
....e.g only varying the mesh cutoff in the calculator and making use of previous calculations by using  initial steps and then using the optimizer

2

General Questions and Answers / photocurrent

« on: January 9, 2018, 20:21 »

how do we test the convergence for photocurrent calculation.
also is the bias volatge applied  to the left and right electrodes in the device calculator setting applicable during photocurrent analysis

3

General Questions and Answers / device k-point convergence

« on: January 9, 2018, 20:17 »

for a device configuration we calculate the k-points for the electrodes and then the centeral region ...it was mentioned in a forum that since the centeral region is non periodic the k-point in the c direction is automatically kept as 1
but when we calculate the configuration as a device then  how do we set the k-points for the device  along  a,b & c  ...also in the tutorial although the convergence is at a much lower value for electrode at  11 along c the value of 51 is taken.

4

General Questions and Answers / Re: Nanowire direction

« on: January 3, 2018, 12:12 »

 the builder does not provide the option for the directions that I have mentioned

5

General Questions and Answers / Re: Nanowire direction

« on: January 3, 2018, 12:10 »

Thank u for your reply sir..... i have to use both the direction that I hv mentioned but since I am using different phases of tio2 to construct the nanowire and also I have to provide surface energy to promote the favourable surface

6

General Questions and Answers / Nanowire direction

« on: December 29, 2017, 11:50 »

how to create nanowires with direction such as [001] & [010]

7

General Questions and Answers / Re: nanowire

« on: December 7, 2017, 21:58 »

However I first want to create nanowires with a single phase and having tetragonal structure for the bulk

8

General Questions and Answers / Re: nanowire

« on: December 7, 2017, 21:46 »

Yes it would be a mixture as I want to vary the percentage of the phases and then create the nanowire....I have tried using generic plugin but was not sure if it was the correct method....also the transformation of the bulk from one lattice to another using supercell matrix transformation ... from tetragonal to fcc or bcc to create nanowires was not possible as the cell was still not cubic after which changing the lattice parameter to cubic although resulted in me being able to use the nanowire plugin ....it still did not yeild  the desired result

9

General Questions and Answers / Re: nanowire

« on: December 1, 2017, 16:03 »

also is there a way to form nanowire with two phases of the same material

10

General Questions and Answers / Re: nanowire

« on: December 1, 2017, 15:55 »

thank u for ur reply ....i have tried the transformation to fcc and bcc from a tetragonal structure (no options for sc) using bulk tool >>supercell.... the transformation has resulted in a unit cell with a=c &  b ...due to which i was unable to transform it into nanowires

11

General Questions and Answers / nanowire

« on: November 29, 2017, 15:57 »

How do we create nanowire from bulk with tetragonal structure ....do i need convert the lattice to simple cubic fractional and then create the nanowire or keep the setting as cartesian in lattice parameters  and change it to simple cublic before creating the nanowire

12

General Questions and Answers / Re: Nanowire (001)

« on: October 17, 2017, 16:11 »

thank u for ur reply but my question was on how to create nanowire in the (001) direction ,since there is no option in the nanowire builder for this direction ....i experimented using the surface cleave option for (100) and compared it with the  nanowire that was created using the nanowire builder.....however unlike in the nanowire builder i cannot set the surface energy and the nanowire created using surface cleave seems to be a bit different....does this mean i have to manually crop the shape of the nanowire which we automatically get using the nanowire builder tool.

13

General Questions and Answers / Nanowire (001)

« on: October 15, 2017, 13:06 »

how do i create nanowires in the direction (001) ......I have tried using surface(cleave).....tried matching the nanowire created from the nanowire plugin and using surface cleave for (100)  ,however there still seems to be some difference ....i am unable to control the surface energy and i have to delete atoms to construct the proper nanowire

14

General Questions and Answers / device from bulk

« on: September 15, 2017, 11:23 »

How is the Zn-ZnO-Zn device in  transport calculation tutorial created.
I've tried using Zn and ZnO(hexagonal) to create the interface ,also made changes with the  shift surfaces( and select surface but could not achieve the same result as in the tutorial.